Apparatus for coating sheets with lubricant for draw dies



E. G. PETERSON APPARATUS FOR COATING SHEETS WITH May 5, 1959 Y LUBRXCANTFOR DRAW DIES 5 Sheets-Sheet l Original Filed 0G13. 7. 1954 NVENTOFl"EDWARD G. PETERSON B27/Q2 M 1./ '/f ATTORNEYS May 5, 1959 E G. PETERSON2,884,898

APPARATUS-FOR COATING SHEETS WITH LUBRICANT FOR DRAW DIES Original FiledOct. 7. 1954 3 Sheets-Sheet 2 INVENTOR EDWARD G. PETERSON BWM Mjww ATTORNEYS May 5, 1959 l E. G.- PETERSON APPARATUS FOR COATING SHEETS WITHLUBRICANT FOR DRAW DIES Original Filed Oct. 7. 1954 NVENTOR- m a S Y R EE N D R Pmw T G UT M L D United States Patent APPARATUS FOR COATINGSHEETS WITH LUBRICANT FOR DRAW DIES Edward G. Peterson, Grand Rapids,Mich., assgnor to Bristol Industrial Equipment Company, Grand Rapids,Mich., a corporation of Michigan Original application October 7, 1954,Serial No. 460,945,

now Patent No. 2,809,129, dated October 8,1957. Dizided and thisapplication April 15, 1957, Serial No.

This inventionv relates to apparatus for coating of metal sheets as apreparatory step for their being formed in a die press. This inventionis designed to provide the machine to apply a non-oily film to thesheet. The film acts as a lubricant to facilitate the sliding movementof the sheet during the actual forming process between the dies.

This application is -a division of patent application Serial No.460,945, now Patent No. 2,809,129, filed October 7, 1954, and entitledMethod of Coating Sheets With Lubricant for Drawv Dies.

With the introduction of modern sheet metal forming and drawingprocesses, particularly those involving what is known as ldeep drawing,it was found essential to lubricate the material prior to itsintroduction between the dies so that the material could slip betweenthe faces of the dies as the press closed. Unless the slippage occurs,the sheets will tear due to non-uniform stretching of the material. i

At first this lubrication was provided by conventional hydrocarbon oils.These oils providedkv a satisfactory lubricant but it was exceedinglydifiicult to remove the oil film after the forming process. Unless suchoil films are entirely removed from the metal, any attempt to apply afinish coating such as enamel results in failure due to lack of adhesionwherever a trace of the lubricant remains. As a consequence, substitutenon-oily lubricants were developed. These are in the nature of a soapand as such may be removed completely, quickly and easily by a simplewashing process. While these soaplike compounds provide an adequatelubricant in thedraw presses and are easily to remove, their initialapplication to the material presents many difiicult problems. it is thesolution of these problems which is the purpose of this invention.

Methods of applying this non-oily film currently in use, -such asspraying or rolling, have not proved satisfactory. The character of thefilm produced byV these methods is not entirely satisfactory.

Further, the methods themselves are difficult to perform. Such methodsnormally apply the film to one face of the sheet at a time,necessitating a repetition of the process to fully prepare the sheets.

This invention provides a method by which the sheet is quickly andrapidly coated simultaneously on both faces. The resulting coating issubstantially uniform and assures proper forming of the sheet in thedie. Further, the coating is formed with a minimum use of material,thus, effecting a certain economy in the quantity of filming materialdemanded by the machine. The machine accomplishes these purposes fullyautomatically, eliminating high direct labor costs and the cost ofstorage and transportation incident to a two step application process.

Other objects and purposes of this invention will be immediately seen bythose acquainted with the preparation of sheet materials for die presses`upon reading the following specification and the accompanying drawings.

2,884,893 Patented May 5, 1959 ICC In the drawings:

Fig. 1 is a somewhat schematic plan view of a machine designed to carryout my invention.

Fig. 2 is a somewhat schematic side elevation view of the machineillustrated in Fig. l.

Fig. 3 is a fragmentary enlarged plan view of the film applying troughslocated in the film application chamber.

Fig. 4 is a fragmentary elevation view taken along the plane IV-IV ofFig. 3.

Fig. 5 is an enlarged sectional elevation view taken along the plane V-Vof Fig. 3.

Fig. 6 is a fragmentary central sectional elevation view of the filmapplying chamber taken along the plane Vl--VI of Fig. 7.

Fig. 7 is an enlarged, sectional, elevation view of one of the conveyorracks for this machine.

Fig. 8 is a fragmentary, enlarged, side elevation view of the conveyorracks for this machine.

Fig. 9 is a plan view of one of the conveyor racks used in this machine.

In executing the objects and purposes of this invention, there has beenprovided a machine consisting basically of a tunnel divided into anumber of compartments. A conveyor passes through this tunnel forcarrying the materials through all of the steps of the film applyingprocess. In the machine, the sheets are washed, drained, rinsed, coveredwith film, drained and dried and delivered at the other end ready foruse in the die presses.

ln applying the film, the material is cascaded in liquid form onto thesheets from overhead troughs. The troughs are filled and the materialcaused to fiow over the tops of the troughs and thus cascade in a thinsheet onto the sheet material below. As it runs down the sheets, thematerial forms a thin, lubricating film which adheres to the sheets. Theexcess material is collected at the bottom of the application chamberand returned to the storage tank for the film material where it isrecycled until it is used up in the formation of a film on the sheetmaterial.

Referring specifically to the drawings, the numeral 10 indicates atunnel having sides 11 and 12, a top 13 (Fig. l) and a bottom it (Fig.6). The top, bottom and sides are tof sheet metal construction supportedby sufficient frame work `to make them rigid. The frame work is notshown as it forms no part of this invention. As is indicated in Fig. l,the main tunnel is divided into ten compartments or `operating areas.The direction of movement of the belt is indicated by the arrow in Fig.l. As the conveyor moves through the tunnel, it passes through an entryarea, a rinse area, a drain area, a cleaning area, a `second drain area,a second rinse area, a third drain area, a film application area, afourth drain area and a drying oven. The entry area is vented through astack 14 and the drying oven is vented through a stack 15. The use ofthese stacks assures the removal of hot or moisture laden air frominside the tunnel before it can exhaust through the ends of lthe tunnel10 into the faces of the operators as they are loading and unloading themachine.

The various areas and compartments have a common passageway through themfor the hereinafter described conveyor 16. They are partially sectionedoff, one from the other, -by sheet metal baffles 25 of any suitableconstruction. Normally these baffles exist only above and y'below theconveyor for the purpose of preventing intermixing of the various liquidused such as the cleaner and rinses. Further description of thesebaffles is not believed necessary since they are of conventional design.

Materials treated in the tunned 10 are transported through the tunnel bymeans of a conveyor 16. The conveyor 16 passes over a pair of pulleys 17and 18 at opposite ends of the tunnel. The pulley 17 is an idler. The

pulley 18 is driven, powering the conveyor. The pulley 18 may be drivenby any suitable means such as an electrical prime mover. The powersource is not illustrated as it is wholly conventional and forms no partof this invention. The return run of the conveyor is spaced just belowthe floor 14 and therefore is exterior of the operating portion of thetunnel 10. The structure of the conveyor will be described more fullyhereinafter.

The rinsing, cleaning and film Iforming solutions used in the machineare stored to one side of the tunnel in tanks 22 (Fig. l).

Film application mechanism The rinsing and draining operations arecarried out by conventional equipment. The rinses are normally appliedby nozzles operating from both the top and sides of the rinsing areas tocompletely spray and clean the sheets. The draining areas are no morethan areas of sufficient length to allow sufiicient time for the liquidsremaining on the sheets to drain off onto the tunnel floor where theyare taken away by suitable drain conduits and either returned to therinsing tanks or discharged entirely.

The particular structure by which the film forming material itself isapplied is quite important to this invention. The lm forming material isin liquid form consisting of the lubricating material in an aqueoussolution. While this invention is particularly designed for use withcurrent film forming materials which are utilized in an aqueoussolution, it is not intended this invention be so limited. It isdesigned for use with any film forming material which will form anadequate film on the sheets when applied by the means incorporated intothis machine. The film forming material is raised from the tank 22 bymeans of a pump 19. The pipe 30 (Fig. 4) distributes the material fromthe pump 19 to the individual troughs 31.

Several troughs 31 are used. These troughs extend laterally across thetunnel just below the tunnels top member 13. The film forming materialis delivered to the troughs under very low pressure. Only sufiicientpressure is provided to assure an adequate supply to the troughs. Thepurpose of this will appear more fully hereinafter. The troughs 31 eachhave a central channel 32. Extending lengthwise of the channel is adistribution conduit 33 having upwardly directed, small, closely spaced,discharge orices 34 throughout its length (Figs. 3 and 5). Thedistribution conduits 33 are closed on each end. Thus, all of the filmmaterial is discharged into the troughs through the orifices 34. Thedistribution conduits 33 are each supplied at the` center by means of apipe 35 connected to the conduit 30. The distribution conduits arelocated deep in the channels 32 whereby discharge of the film materialthrough the orices 34 will not cause rippling or waving of the topsurface of the body of iilm material filling the channel.

Four troughs are utilized. It will be recognized that while this numberhas been found suicient in this machine, under other circumstances agreater or a lesser number of the troughs may be required. Each of thetwo intermediate troughs are provided with a pair of downwardly andoutwardly inclined batlies 36. The bafiies are inclined downwardly atapproximately 45 and extend outwardly and downwardly from the channel 32adjacent the bottom of the channel. The trough in Fig. 5 is illustratedwith the channel 32 and the baffles 36 formed from a single piece ofmaterial. This is a desirable way of fabricating this particularstructure although it may be fabricated from as many different parts asis desirable.

The ends of the channel 32 are closed by a terminal plate 37. Eachterminal plate is large enough to cover the entire cross-sectional areaof the trough 31 including the -bafies 36. The terminal plates aresecured to the U- shaped membersforming the channel 32 and the baies 36by *suitable means such as welding. Each of the terminal plates 37 isprovided with a pair of vertically elongated slots 38. These provide themeans for attachment of the troughs to the side members 11 and 12 of thetunnel. Attachment is effected by means of bolts 39 passing through theside members 11 and 12. By means of the slots 38, the troughs may beleveled so that the film forming material will ow over both edges of thechannel in equal quantity.

Below the troughs 31 and below the conveyor 16, the floor 14 of thetunnel slopes downwardly to one side of the tunnel thus causing theexcess film material to collect along this side where it is drainedthrough the pipe 50 and returned to the proper storage tank 22 for thefilm material (Fig. 6).

The end troughs 31a are identical to the troughs 31 except that theoutside wall 51 of the channel 32 is made slightly higher than theinside wall 52. This prevents the filming material from overflowing onthis side of the trough, confining the discharge of these troughs to theinside edge. Since the walls 51 are raised to prevent the discharge ofthe film material on the outer side of the troughs, the flanges 36 areomitted along the outer side.

The conveyor The upper run of the conveyor 16 is supported on a track 60consisting of a pair of L-shaped rails 61 (Figs. 7 and 8). The rails 61are located one on each side of the tunnel and are secured `to the sides11 and 12 of the tunnel. The conveyor has a pair of side chains 62. Eachside chain 62 consists of alternately arranged link pairs 63 and 63apivotally joined adjacent their ends by pins 64. Rotatably mountedbetween the links on each of the pins 64 is a carrier wheel 65. Thecarrier wheels 65 support the chain on the rails 61 of the track 60. Theinner link of each of the link pairs 63 and 63a is equipped with aninwardly turned, horizontal ear 66. The ears 66 on the inner link of thelink pairs 63a is slightly longer than the ear on the inner link of thelink pair 63 to account for the differential in location of these linkssince one pair is mounted exteriorly of the other.

The main body of the conveyor is formed by racks 67 which extend betweenthe conveyor chains 62. The -racks each consist of a lateral supportingbar 68 to each end of which is secured an L-shaped anchor bracket 69.The bottom, horizontal leg of each of the anchor brackets 69 rests uponone of the ears 66 and is secured thereto by means of a bolt 70. Theracks 67 each have a foot portion formed by a rod 71 extending acrossthe conveyor between the anchor brackets 69, parallel to the supportingbar 68 and spaced a short distance therefrom (Fig. 9). The rod 71 isconnected to the supporting bar 68 by short rod segments 72. The ends ofthe rod 71 are bent back to contact the vertical leg of the brackets 69.The rod segments 72 are secured to both the supporting bar 68 and therod 71 by welding. In a similar manner, the ends of the rods 71 aresecured to the anchor brackets 69 by welding.

The individual sheets 74 (Fig. 8) are supported by vertically extendingnesting frames 75a are mounted to each support bar 68. The nestingframes 75 and 75a are identical except that the bottom ends of thenesting frames 75 are turned horizontally and extend across the foot ofthe rack to contact the rod 7ll (Fig. 9). Each of the nesting frames isof generally triangular shape having one inclined and one vertical leg.The lower ends of the nesting frames 75 and 75a are firmly secured tothe support bar 68 by suitable means such as welding.

The nesting frames 75 and 75a adjacent both their upper and their lowerends have an offset portion 77, offset longitudinally of `the conveyor.The inclined legs of the nesting frames 7S and 75a are provided with acorresponding pair of offset portions ',78V also offset longitudinallyof the conveyor but in the opposite direction from the offset portions77. The racks 67 are so spaced, longitudinally of the conveyor, that theoffset portions 77 of one rack cooperating with the yoffset portions 78of the adjacent rack form a slot 79 (Fig. 8) slightly wider than thethickness of the sheet 74 whereby the sheet will seat between twoadjacent racks with its lower end resting on the rod 71 of the racksfoot portion. The sheet is held in vertical position by the offsetportions. The offset portions 77 are spaced from the offset portions 78transversely of the conveyor (Fig. 9). This arrangement provides meansfor holding the sheets in vertical position as they pass through thetunnel with the sheets fully exposed since the racks are formed of athin, rod-like material and with the sheet being held in position by aminimum number of points of -contact between the racks and the sheet.This arrangement assures a thorough `coating of the sheet with thefilming material.

At the center, between the pair of nesting frames 75a, a T-shaped brace80 is provided to support the nesting frames 75a and generallystrengthen the structure.

The upper run of the .conveyor moving through the tunnel has thenestingl frames 67 projecting upwardly above the wheels 65. On thereturn run, the nesting frames `67 hang downwardly from the Wheels 65with the conveyor supported from above by the return track structure 81(Fig. 6).

Operation Before the machine is put into operation, it is essential that-the troughs 31 be properly leveled. These troughs must be level bothcrosswise and lengthwise of the tunnel so that the liquid will bedischarged in an even film over all edges of Ithese troughs. For thispurpose, the bolts 39 are loosened to permit the trough to be adjustedin any direction necessary to produce this level condition. It will beseen, when the process carried out in this machine is described, thatthis leveling of the troughs is essential to produce a satisfactory filmon the sheets.

The sheets are initially placed on ythe conveyor at the loading end 80.As the racks 67 pivot about the idler pulley 17, they are caused toseparate. With the racks 67 separated, the sheets may be easily placedbetween them. As the Iconveyor completes its turn about the idler pulley17, the racks again close up to hold the sheets closely between them.The movement of the conveyor then carries the sheets Iinto the tunnel10.

In the lirst rinse chamber, the sheets are thoroughly rinsed to removeany foreign particles such as shavings, chips or other coarse materialwhich may be deposited on their surfaces. As they progress through thetunnel, in the first drain chamber this rinse water is drained oil. Theythen pass into the cleaner chamber. In the cleaner chamber, the sheetsare sprayed with a cleaning solution designed to strip from them 'anyremaining foreign material and any oils or other films which may be ontheir surfaces. From the cleaner chamber, the sheets pass through asecond draining chamber where the cleaner is drained and then into arinsing chamber where the last traces of cleaner `are removed by athorough flushing.

The sheets then progress into the film application chamber. In thischamber the troughs 31 and 31a are kept constantly full with sufficientfilm material being supplied tothe troughs to force the material to runover the edges of the trough. Suicient material is supplied to assure aconstant thin film of material spilling over the tops of the channel 32.This film of material cascades down the sides of the channel and overthe baffles 36. The baffles 36 perform the service of joining anydivergent streams of the material which may form and cause it to cascadeonto the sheets 74 in a continuous, unbroken film. Such a cascadingprocess assures a complete coverage of the surfaces of the sheets 74.The rate at which the filming material is supplied to the troughs andthe force with which it is discharged through the orifices 34, is suchthat the filming material in the channel 32 forms a level lake so that-it will spill in an even quantity along the entire length of thetroughs. It is seen that the troughs must be level, both longitudinallyand crosswise to assure the constant discharge of the film in evenquantities from all the portions of the troughs.

More material is discharged from the troughs than adheres to the sheetsto form the lm. This excess material cascades down the sheets andthrough the conveyor. Since the conveyor is open at the bottom, thematerial drains freely through the conveyor onto the floor 14 of thetunnel where it runs to one side and is discharged through the returnconduit 50. This excess film material is returned to the storage tankZ2. for the film material. 'Iheopen design of the feet of the racks 67permits the material to drain away easily and quickly from beneath thesheets 74, thus assuring the complete discharge ofv all material whichdoes not adhere to the surfaces of the sheets.

The high outer sides 51 of the troughs 31a contines the cascading actionto the central portion of the lm application chamber. Thus, the filmwill not be accidently caused to splash into the adjacent rinsing anddraining chambers.

After the sheets have been subjected to the cascading tlm applyingoperation, they move through a draining area where the last of theexcess lm material is drained oli. As in the application chamber, thisdrained oft material is collected on the floor of the tunnel andreturned to the film storage tank. The conveyor then passes through adrying oven where the sheets are heated to sufficient temperature to setthe lming material and dry ofr the remaining moisture. The openconstruction of the racks 67 assumes even and adequate heating of allparts of the sheets 74. The open foot portion of the racks assurescirculation of the heated air about the bottom of the sheets.

Heating may be effected in the drying oven by any suitable means such asby supplying the oven with adequate quantities of hot, dry air. This isa preferable arrangement because the heat source may be providedseparate and apart from the tunnel and may be closely regulated to therequirements of the material being processed. However, it is entirelypossible to substitute infrared heating units within the drying oven.

As the conveyor 16 emerges from the drying oven, the stack 15 removesthe hot air so that it does not discharge into the operators face. Thesheets, as they exit from the tunnel, are completely coated and driedready for use in the die press. The conveyor then passes over the drivenpulley 18 at its discharge end 82. As the conveyor turns about thepulley, the racks 67 are caused to separate, thus permitting the sheets74. to be removed quickly and easily by the operator. The conveyor thenreturns to the loading end of the conveyor beneath the oor of the tunnelin inverted position.

The open design of the racks assures a complete coverage of the sheetsand at the same time assures complete drainage of the sheets so therewill be no wet points on the sheets after they have passed through thedrying oven. Further, the design of the rack 67 is such that theconveyor is capable of carrying a large quantity of sheets since thesheets are spaced only about three inches apart along the conveyor.Thus, the machine, although necessarily moving slowly through thetunnel, is capa.- ble of processing as a continuous operation a largequantity of material in a short period of time.

It will be seen that the operation, as carried out in this machine, isentirely automatic, the only operator necessary being a loader andunloader. It will be recognized that even these operators may beeliminated by the use, in association with this machine, of automaticmechanical loading and unloading equipment.

The coating of the sheets with a cascading action of a continuous filmof the film forming material assures complete coverage. Furthermore, itmakes it possible to coat the sheets simultaneously on both faces, thusdoing the entire job in a single passage through the machine. Theconstruction of the machine is such that practically none of the filmforming material is Wasted since that which does not adhere to thesheets is collected and cycled for reuse. The use of excess quantitiesof the film made possible by cascading action assures complete coverage.As a result, there are no uncoated spots to cause difiiculty when thesheets are placed in the die presses. The operation is carried outswiftly and completely, permitting large quantities of sheet material tobe prepared rapidly and completely with practically no opportunity fordefective coating of the sheets.

While I have described a preferred embodiment of my machine, it will berecognized that various modifications of this invention may be made.Such modications are to be considered as included in the hereinafterappended claims unless these claims by their language expressly stateotherwise.

I claim:

1. In a machine for automatically coating sheet material with a filmforming lubricant, the combination comprising: a tunnel open at eachend; a powdered conveyor and means supporting one run of said conveyorfor travel through said tunnel; said conveyor having a plurality ofclosely spaced racks thereon; said racks be ing adapted to support saidsheets in vertical position with each individual sheet separated fromeach adjacent sheet longitudinally of the conveyor; an elongated troughin said tunnel adjacent the top thereof; means mounting said trough tosaid tunnel transversely thereof; said means adapted to hold said troughlevel both longitudinally and transversely thereof; a supply of saidfilm forming lubricant and a conduit for supplying and filling saidtrough with said film forming lubricant; means on the sides of saidtrough for causing said film forming lubricant to cascade from saidtrough in a substantially uniform sheet; a `drain below said conveyorfor removing excess quantities of said film forming material.

2. In a machine for automatically coating sheet material with a filmforming lubricant, the combination comprising: a tunnel open at eachend; a powered conveyor and means supporting one run of said conveyorfor travel through said tunnel; said `conveyor having a plurality ofclosely spaced racks thereon; said racks being adapted to support saidsheets in vertical position with each individual sheet separated fromeach adjacent sheet longitudinally of the conveyor; a plurality oftroughs in said tunnel adjacent the top thereof; means mounting saidtroughs to said tunnel transversely thereof; said troughs being spacedlongitudinally of said tunnel; said means adapted to hold said troughslevel both longitudinally and transversely thereof; a supply of saidfilm forming lubricant and a conduit for supplying and filling each ofsaid troughs with said film forming lubricant; means on the sides ofsaid troughs for causing said film forming lubricant to cascade fromsaid Itroughs in a plurality of substantially uniform sheets; a drainbelow said conveyor for removing excess quantities of said film formingmaterial.

3. In a machine for automatically coating sheet material with a filmforming lubricant, the combination comprising: a tunnel open at eachend; a powered conveyor and means supporting one run of said conveyorfor travel through said tunnel; said conveyor having a plurality ofclosely spaced racks thereon; said racks being adapted to support saidsheets in ventical position with each individual sheet separated fromeach adjacent sheet longitudinally of the conveyor; a plurality oftroughs in said tunnel adjacent the :top thereof; means mounting saidtroughs to said tunnel transversely thereof; said troughs being spacedlongitudinally of said tunnel; said means adapted to hold said troughslevel both longitudinally and transversely thereof; each of said troughshaving a central chamber open at the top; the sides of the chambers ofcertain of said troughs being of uniform height; one side of the chamberof the trough at each end of said plurality of troughs being higher thanthe other of the sides thereof; a supply of said film forming lubricantand a conduit for supplying and filling each of said troughs with saidfilm forming lubricant; means on the sides of said troughs for causingsaid film forming lubricant to cascade from said troughs in a pluralityof substantially uniform sheets; a drain below said conveyor forremoving excess quantities of said film forming material; a drying ovenin said tunnel downstream of said conveyor from said troughs.

4. In an elongated trough for cascading a liquid material in asubstantially uniform sheet along the entire length thereof, thecombination comprising: a U-shaped channel open at the top; supportplates secured to and closing each end of said channel; an outwardly anddownwardly projecting baflie along each side of said channel andextending the entire length thereof; a supply conduit within saidchannel adjacent the bottom thereof; the length of said supply conduitbeing equal to a major portion of the length of said channel; saidconduit having a plurality of restricted discharge orifices therein;said discharge orifices being equally spaced along said supply conduit.

5. In an elongated trough for cascading a liquid material in asubstantially uniform sheet along the entire length thereof, thecombination comprising: a U-shaped channel open at the top; supportplates secured to and closing each end of said channel; an outwardly anddownwardly projecting baffie along each side of said channel andextending the entire length thereof; a supply conduit within saidchannel adjacent the bottom thereof; (the length of said supply conduitbeing equal to a major portion of the length of said channel; saidconduit having a plurality of restricted discharge orices therein; saiddischarge orilices being arranged in two parallel rows; the axis of saidorifices diverging in an upwardly direction; said discharge orificesbeing equally spaced along said supply conduit in each row.

References Cited in the file of this patent UNITED STATES PATENTS Re.23,184 Whitbeck Dec. 20, 1949 1,290,952 Fangboner Jan. 14, 19191,340,645 Alleman May 18, 1920 1,401,703 Hyre Dec. 27, 1921 1,448,065Harrich Mar. 13, 1923 1,699,972 Jones et al. Jan. 22, 1929 1,753,998Podel Apr. 8, 1930 1,859,652 Bullerjahn May 24, 1932 2,279,686 KerlinApr. 14, 1942 2,309,259 Seigh Jan. 26, 1943 2,338,015 Whitaker Dec. 28,1943 2,450,438 Miller Oct. 5, 1948 2,721,809 Marks et al. Oct. 25, 19552,809,129 Peterson Oct. 8, 1957

